Postmortem evaluation of the striatum in an NTCELL trial participant five years after transplantation.

In 2017 a novel growth factor administration therapy (termed NTCELL®) was trialled for safety and efficacy for Parkinson's disease treatment. NTCELL® administration is the transplantation of encapsulated porcine choroid plexus cells into the putamen. A clinical study demonstrated safety but failed to meet its primary clinical end-point. Here we describe the clinical and neuropathological characteristics of a case who died five years after receiving NTCELL® treatment. Using histochemical and immunohistochemical labelling, we demonstrate that the NTCELL® capsules remain in the striatum but are mainly devoid of cellular contents. A similar pattern of astrogliosis and microgliosis surrounds the capsule placement area to those surrounding the needle track for implanting the capsules. This study is important as it is the first exploration of the long-term clinical and anatomical outcomes of the NTCELL® clinical trial. The results of this study will help inform future studies aimed at regenerating neurons through the implantation of capsules.